1. Field of the Invention
The present invention relates to a device for massaging a lower leg comprising a base pad arranged in an area of the sole and a bladder arranged in the region of the lower leg, a tubular connection being provided between the inner spaces of the base pad and of the bladder.
2. Description of the Prior Art
Devices for the treatment of hypostatic leg conditions such as varicose veins, chronic phlebitis, chronic venous insufficiencies as well as for the aftertreatment and prevention of thrombosis are becoming increasingly important as a result of the wide occurrence of such diseases. In these diseases, the blood pumped toward the heart rushes back as a result of the change occurred in the veins. As these anatomic changes are irreversible, the permanent reflux increasingly causes the blood to stagnate in the damaged veins of the lower leg. This stagnation causes the blood to pass through the veins into the surrounding muscles, which harden as a result thereof. The increasingly hardened muscles are not capable of exerting an elastic pressure onto the congested veins and cannot force the blood upwards toward the heart.
These anatomic changes result in permanent functional disorders in the form of an increasing fluid stagnation and of an external swelling of the lower legs. In order to prevent or cure these functional disorders by means of internal or external treatment, other methods have been tried such as the wearing of compression stockings; bandages and insole supports; scierotherapy and surgery, as well as infusions.
The documents DE-OS 195539, FR-OS 2108764, DE 3440638 A1, DE 2122907 B2 and CH 618 879 A5 describe devices that enclose the entire lower leg and massage this area by exerting a pressure, thus assisting the venous return of the blood. The disadvantage of the devices mentioned is not only the irksome procedure for a patient of putting it on to the leg but also the fact that the entire lower leg is being massaged, which requires a very efficient pressure source with a high energy need. An appropriate, efficient pressure source, a pressure pump for example, may strongly limit the freedom of movement of a patient because of its size or the size of its energy source, an accumulator for example. Also, with such devices, the duration of the therapeutic effect is limited by the life of the energy source.
WO 90/09115 describes footwear provided with an upper in which a bladder filled with a fluid is arranged, the bladder communicating with a pump by way of a regulator, the regulator being configured to maintain the pressure generated by the pump constant within the bladder. The footwear is said to provide optimal hold and optimal support for a foot. For this reason, the bladder substantially completely encompasses the instep and the ankle area of the foot. With this footwear, which provides a constant pressure exerted over a large area of the foot, it is not possible to exert a pulsating pressure that assists on purpose the blood return to the heart.
U.S. Pat. No. 5,366,439 A discloses an ankle brace intended to prevent ankle injury. This ankle brace is provided with a frame with a heel stirrup provided with a lower portion and with inner and outer upright portions that are oriented substantially parallel to the lower leg. The inner lateral portions are provided with a vinyl bubble film as it is known for example in the packaging sector, the inner portions being pressed by the outer portion against areas of the lower leg and of the ankle.
This ankle brace is not suited for the treatment of hypostatic leg conditions as its design does not permit to enhance the flow of blood toward the heart. In putting on the ankle brace very tightly, the blood may be prevented from flowing into the foot but this has the disadvantage that the blood may stagnate above the ankle. From a therapeutic point of view, it is not indicated to cause blood to stagnate above the ankle area with hypostatic leg conditions, as this generally increases the stagnation pressure in the veins, which may increasingly cause blood to pass from the veins into the surrounding muscle tissue.
U.S. Pat. No. 5,353,525 A discloses an athletic shoe which is provided, in the heel area of its sole, with a flat pump chamber communicating with inflatable bladders which are arranged in the upper portion of the shoe in such a manner that they support the instep and the ankle. In order not to generate too high a pressure in the bladders, valves are provided which open when the pressure exceeds a predetermined threshold pressure and permit air to exit the bladders. The shoe described serves to protect the foot and ankle area when the user is active. It is particularly intended to prevent ankle strain. Like in the above mentioned WO 90/09115, this shoe is not suited to enhance the venous blood circulation as with this design it is not possible to exert on purpose a pressure onto the veins or onto such locations in the foot or the ankle area that make sense from a therapeutical point of view.
Not the least reason why the devices disclosed in the three last mentioned documents are not suited for the treatment of hypostatic leg conditions is that the object of these inventions is to protect the foot and ankle area, more specifically during sport activities.